Solid oxide fuel cell

Abstract

A solid oxide fuel cell includes two or more power generating elements each having a cathode, an anode, and an electrolyte layer placed between the cathode and the anode; an interconnector electrically connecting the power generating elements and containing a chromite-based material; and a sealing portion provided between the electrolyte layer and the interconnector and not containing either Ni or ZrO 2 .

What is claimed is: 
     
       1. A solid oxide fuel cell comprising:
 two or more power generating elements each having a cathode, an anode, and an electrolyte layer placed between the cathode and the anode; 
 an interconnector electrically connecting the power generating elements and containing a chromite-based material; and 
 a sealing portion provided between the electrolyte layer and the interconnector and not containing either Ni or ZrO 2 , 
 wherein the sealing portion contains at least 50 wt % of at least one oxide selected from the group consisting of (AE)ZrO 3 , MgO, MgAl 2 O 4  and Ce x Ln 1-x O 2 , where AE is an alkaline earth metal, Ln is at least one element selected from the group consisting of Y and lanthanoids, and x satisfies 0<x≦0.3, and 
 wherein the sealing portion is positioned on both sides of the interconnector. 
 
     
     
       2. The solid oxide fuel cell of  claim 1 , wherein the sealing portion is provided so as to be in contact with the interconnector. 
     
     
       3. The solid oxide fuel cell of  claim 1 , wherein the sealing portion contains (AE)ZrO 3  and MgO. 
     
     
       4. The solid oxide fuel cell of  claim 3 , wherein the sealing portion has 5 to 99 wt % of (AE)ZrO 3  and 1 to 95 wt % of MgO. 
     
     
       5. The solid oxide fuel cell of  claim 3 , wherein the weight ratio of (AE)ZrO 3 :MgO is 5:95 to 99:1. 
     
     
       6. The solid oxide fuel cell of  claim 1 , wherein AE is at least one element selected from the group consisting of Mg, Ca, Sr and Ba. 
     
     
       7. The solid oxide fuel cell of  claim 1 , wherein
 the chromite-based material is represented by the following general formula (1):
   Ln 1-x A x Cr 1-y-z B y O 3   (1)
 
 
 wherein Ln is at least one element selected from the group consisting of Y and lanthanoids; the A site contains at least one element selected from the group consisting of Ca, Sr and Ba; the B site contains at least one element selected from the group consisting of Ti, V, Mn, Fe, Co, Cu, Ni, Zn, Mg and Al; and 0.025≦x≦0.3, 0≦y≦0.22, and 0≦z≦0.15. 
 
     
     
       8. The solid oxide fuel cell of  claim 1 , further comprising a substrate, wherein
 the power generating elements are provided on the substrate, and 
 the interconnector is arranged so as to electrically connect the power generating elements provided on the substrate. 
 
     
     
       9. A segmented-in-series solid oxide fuel cell comprising a plurality of power generating elements formed on an insulating substrate, the power generating elements each having a cathode, an electrolyte layer and an anode, and connected via an electrically connecting portion including an interconnector, wherein
 the interconnector is dense, connected to the anode, and containing a chromite-based material, the chromite represented by the following general formula (1):
   Ln 1-x A x Cr 1-y-z B y O 3   (1)
 
 
 wherein Ln is at least one element selected from the group consisting of Y and lanthanoids; the A site contains at least one element selected from the group consisting of Ca, Sr and Ba; the B site contains at least one element selected from the group consisting of Ti, V, Mn, Fe, Co, Cu, Ni, Zn, Mg and Al; and 0.025≦x≦0.3, 0≦y≦0.22, and 0≦z≦0.15, 
 wherein a sealing portion containing at least 50 wt % of CaZrO 3  and MgO is provided between the electrolyte layer and the interconnector, and 
 wherein the sealing portion is positioned on both sides of the interconnector. 
 
     
     
       10. The solid oxide fuel cell of  claim 9 , wherein the insulating substrate is porous and has gas flow channels inside. 
     
     
       11. The solid oxide fuel cell of  claim 1 , wherein each power generating element comprises an anode current collecting layer positioned below and in contact with the anode. 
     
     
       12. The solid oxide fuel cell of  claim 1 , wherein the entirety of the interconnector is spaced from the electrolyte layer.